Abstract:

Objective    To explore the value of magnetic resonance imaging(MRI) in the diagnosis of fetal urinary abnormalities. Methods    MR scanning was performed on living fetuses with gestational ages ranging 27- 38 weeks, who were diagnosed as having urinary abnormalities by prenatal ultrasonography(US) . Single shot ( SSh) FSE T2WI and fast field echo (FFE) T1WI sequences with the Philips Achieva 1.5T MR scanner were used to obtain abdominal images on axial and coronal planes. The results of prenatal MRI of 33 cases were compared with postnatal US or autopsy after abortion, and the accuracy of MRI was evaluated. Results   Of the 33 cases with urinary abnormalities diagnosed by MRI，there were 4 cases of multi-cystic renal dysplasia, 5 cases of polycystic kidney disease，3 cases of renal dysplasia, 4 cases of ectopic kidney and agenesis of kidney respective, 2 cases of horseshoe kidney,4 cases of ureteropelvic junction anomaly, 2 cases of renal duplication, and 5 cases of ureterovesical junction anomaly. Compared with the results of postnatal US and autopsy, 30 cases(90.9%) were correctly diagnosed and 3 cases incorrectly. Conclusion   MRI hes high value in the diagnosis of fetal urinary anomalies, and it could be used as an important complementary modality for prenatal US.

Key words:  Fetus；Urinary anomaly；Magnetic resonance imaging